Jeff Lawrence on fri 7 aug 98
Eleanora Eden was offering her volumetric method of plaster mixing:
>Seems it's time for me to repost Eleanora's EZ Breasy Plaster Casting
Method. Having no patience at all with the weighing of water I do it in
>the following manner:
1. Judge volume of pour (if you keep a log of your pours it will help). > >
2. Volume of plaster desired = volume of dry plaster. Only FRESH #1
>pottery plaster should be used. Know your source. Ask how long the bags
>have been around. >
>3. Volume of water = 2/3 volume of dry plaster. >
>so. measure your water and pour it in a container large enough. Dump
>plaster in and mix for afew minutes. When it's thickened like cream it's
>ready. When it's thickened like pudding it's more than ready. >
>This is not to say that I don't think people should bother to learn more
>than this about plaster. But this works fine for me >and I make alot of
molds. > >
Eleanora,
If you make one-offs for fun or whatever, sure, eyeball the parts and dump
them together. I use your method whenever I need a waste mold.
But for producing clay ware, your method will produce a mold that functions
in a unique, unpredictable and unduplicable way. Maybe it will absorb well,
maybe poorly, maybe fast, maybe slow. Maybe it will wear well, maybe flake
off into your clay and contaminate your batch.
Alternatively, if you weigh your materials correctly, you'll get a mold with
predictable absorption and durability.
Jeff, whose molds still come out scruffy despite careful weighing
Jeff Lawrence
jml@sundagger.com
Sun Dagger Design
Rt 3 Box 220
Espanola, NM 87532
ph 505-753-5913
eden@sover.net on sat 8 aug 98
Jeff and all,
Who's talking about "eyeballing" anything? I measure very carefully by
volume and make production molds all of which last for years and years, by
which I make a good portion of my living.
I am always reticent about sharing this method because somebody always puts
it down. But on the other hand it is easy and reliable and a potter who
might not bother to do plaster because it is such a hassle with all the
weighing may well be moved to try a more direct method.
Eleanora
Eleanora Eden 802 869-2003
Paradise Hill
Bellows Falls, VT 05101 eden@sover.net
"Never look down on anybody unless you're offering them a hand to help them
up."
Pete Hamill's mom
Llewellyn Kouba on wed 5 nov 03
I should have been paying more attention to other posts on Mold making but
haven't. I am going to make two molds to start with for plaster cast for
use on large 9x13 tile or really pavers as I want them pretty thick. I
think it was Snail who mentioned he also had used pressed wood covered with
formica. I had started my project using this material thinking it would be
resistant to the plaster and not stick. I have yet to pour them but am
sure this will work. I am trying to think of all the different angles
needed and hope I don't miss too many. Another item- I am beveling the wood
(forms) molds so they will knock out easier that a straight cut when the
things are dry and have to be removed. I am also drawing pencil lines
inside and out as to the plaster depth I will pour so they will be
uniform. I am also doing them in two parts in that the center (finished
carved relief mold) will be removable and I can then do other different
designs and fit into the outer shell for other tile patterns. I am keeping
the bottom about 2 inches thick (not sure it needs to be more) Maybe 3
inches if large so it takes hammering (I may pour them rather than press
mold them anyway?) I will spray on a mold release, pour the plaster and see
how bad I did. Any other tips would be great. One more thing ...since I
am in two parts I wonder if I have to have the bottoms nailed down or if I
can just sit the form on another piece of contact board and pour? I guess
I would seal the bottom and side edges with clay. The idea being you can
pick the piece us and knock it free when the plaster has set. I am trying
to make it a simple as possible or remove a couple nails where possible so
I don't fight wood/plaster setting drying issues. Hope this all makes sense.
Llewellyn Kouba
Abbey Pottery
Snail Scott on wed 5 nov 03
At 08:56 AM 11/5/03 -0700, you wrote:
>I am beveling the wood
>(forms) molds so they will knock out easier that a straight cut when the
>things are dry and have to be removed...
Not sure why you are doing this. You aren't nailing the
boards together, are you? Just use straight lengths of
board, with a clamping strip nailed/glued to one end of
each. Arrange them so that they are 'pinwheeled' around
the pattern, and use 'C' clamps to hold them together.
A little clay will suffice to seal the cracks, and no
need to fasten the frame to the bottom board. This system
allows for full variation in the size of each mold you
make, up to the largest dimension of your cottle boards.
And since these are tiles (one-part molds), I think
Diane's idea of using Rubbermaid bins for cottles is
brilliant.
-Snail
Eleanora Eden on tue 25 nov 03
I just read this thread on plaster mold making. Actually there IS a reason
to fasten the frame that will hold the plaster to the bottom board. The
frame can tend to float up when the plaster is poured, and caulking wth
clay will not necessarily prevent this. I have seen this many times. The
bigger the mold the more tendency to this, and a 9x13 tile mold would
be. We always screw it down to the bottom board.
Eleanora
> no
>need to fasten the frame to the bottom board.
........
Eleanora Eden 802 869-2003
Paradise Hill Road eeden@vermontel.net
Bellows Falls, VT 05101 www.eleanoraeden.com
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